155Mbps to 2.5Gbps Burst-Mode
Laser Driver
BEN+
BEN-
IBIAS
+
IMOD
ENABLE DELAY
BEN ±MIDPOINT
10% OF IBIAS
IFINAL × 110%
IFINAL
IFINAL × 90%
DISABLE DELAY
Figure 1. Enable and Disable Delay Times
VCC
22.1Ω
OUT-
MAX3656
OUT+
BIAS+
BIAS-
49.9Ω VCC
IMOD
VCC
22.1Ω
Z0 = 50Ω
26.7Ω
IBIAS
Z0 = 50Ω
121Ω VCC
OSCILLOSCOPE
50Ω
50Ω
26.7Ω
35.7Ω
Figure 2. Output Termination for Characterization
(TA = +25°C, unless otherwise noted.)
OPTICAL EYE DIAGRAM
(155.52Mbps, 117MHz FILTER,
PATTERN = PRBS 27 - 1 + 80 CID)
MAX3656 toc01
Typical Operating Characteristics
OPTICAL EYE DIAGRAM
(622.08Mbps, 467MHz FILTER,
PATTERN = PRBS 27 - 1 + 80 CID)
MAX3656 toc02
OPTICAL EYE DIAGRAM
(1.25Gbps, 933MHz FILTER,
PATTERN = PRBS 27 - 1 + 80 CID)
MAX3656 toc03
EXCELIGHT SLT3120-DN LASER
AVERAGE OPTICAL POWER = -4dBm
EXTINCTION RATIO = 15.2dB
MASK MARGIN = 42%
EXCELIGHT SLT3120-DN LASER
AVERAGE POWER = -4dBm
EXTINCTION RATIO = 15.1dB
MASK MARGIN = 30%
EXCELIGHT SLT3120-DN LASER
AVERAGE POWER = -3.5dBm
EXTINCTION RATIO = 14dB
MASK MARGIN = 23%
_______________________________________________________________________________________ 5